I doubt a tablet would be powerful enough to record 2 or 3 webcams. Maybe it would work if youre recording in 640x480 at only 15 FPS or something, but not 720p or higher.
MiniCam for Windows works fine for what you want. With 3 cams you just need to add some parameters (as explained on the website) and config accordingly.
BTW, if you like it and will use it, you should send this guy some money. Hes a very nice guy and his support is awesome.